Trinapthylmethane compounds

Abstract

This invention relates to derivatives of phthalaldehydic and naphthalaldehydic acid useful as intermediates in the preparation of pH-sensitive phthalide and naphthalide indicator dyes. A class of intermediates provided by the present invention comprises compounds of the formula: ##STR1## wherein A represents 4'-hydroxy-1'-naphthyl; B represents 4'-hydroxy-1'-naphthyl or indol-3-yl and C represents a 2-carboxy-1-phenyl radical or an 8-carboxy-1-naphthyl radical and preferably is 8-carboxy-1-naphthyl.

What is claimed is: 
     
       1. A compound of the formula: ##STR18## wherein A represent 4'-hydroxy-1'-naphthyl and B represents 4'-hydroxy-1'-naphthyl. 
     
     
       2. A compound as defined in claim 1 wherein said B represents 4'-hydroxy-1'-naphthyl. 
     
     
       3. A compound as defined in claim 2 wherein said 4'-hydroxy-1'-naphthyl A is substituted in the 3'- or 5'- position with a hydrogen-bonding group. 
     
     
       4. A compound as defined in claim 3 wherein said hydrogen-bonding group is substituted in the 3'position. 
     
     
       5. A compound as defined in claim 2 wherein said 4'-hydroxy-1'-naphthyl B is substituted in the 3'- or 5'-position with a hydrogen-bonding group. 
     
     
       6. A compound of the formula: ##STR19## wherein R 1  and R 2  each are selected from hydrogen and a hydrogen-bonding group selected from carboxy, hydroxy, o-hydroxyphenyl, bis trifluoromethyl carbinol, sulfonamido and sulfamoyl, at least one of R 1  and R 2  being hydrogen, and B is ##STR20## wherein R 3  and R 4  have the same meaning given for R 1  and R 2 , and R 5  is hydrogen or alkoxy containing 1 to 18 carbon atoms. 
     
     
       7. A compound as defined in claim 6 wherein R 1  is hydrogen and R 2  is a hydrogen-bonding group. 
     
     
       8. A compound as defined in claim 7 wherein said B is ##STR21## 
     
     
       9. A compound as defined in claim 8 wherein R 4  is hydrogen and R 3  is a hydrogen-bonding group. 
     
     
       10. A compound as defined in claim 9 wherein R 2  is carboxy and R 3  is carboxy. 
     
     
       11. A compound as defined in claim 9 wherein R 2  is sulfamoyl and R 3  is sulfamoyl. 
     
     
       12. The compound of the formula: ##STR22## 
     
     
       13. The compound of the formula: ##STR23##